I started using the a meter to measure ketones for my two year old who has type�1 diabetes, and her endocrinologist was very hesitant with changing from using urine strips to the meter which uses blood because of her young age. So, I was asked to use both methods to check ketones. I found that when the meter showed 0.0 to 0.6, the urine test strips showed moderate to large levels. Why is this? Which test is most accurate?

Your dilemma is reminiscent of the time when urine testing for sugar was giving way to home blood glucose monitoring. There are several possible reasons for the apparent discrepancy between the urine dipstick test and the meter reading for ketones.

To begin with, you need a little more blood than for glucose, and the reading takes a few seconds longer. Perhaps you should check with the your daughter’s nurse-educator to be sure you are indeed doing both tests absolutely correctly, especially timing the urine test accurately.

Much more importantly though, a urine sample reflects what has been going on in the blood stream since the bladder was last emptied and, with a first morning sample, this may lead to a significant difference from a blood sample at the end of this period, especially in the case of ketone bodies which are so rapidly cleared by the kidney and the lungs. The dipstick test is calibrated to be extremely sensitive, and it has been used for such a long time that I think most doctors are much more accustomed to it than a blood level. Nevertheless, the blood level is more accurate and more informative.

It is important to solve this issue because any time your daughter is sick or has blood sugars greater than 240 mg/dl [13.3 mmol/L], you need to monitor ketones as well as blood sugar in order to be sure that if you have to give extra insulin you give enough to correct both ketone and glucose levels.

DOB